Evaluation of ossification in jaw defects by radio-nuclide imaging

The uptake of the bone-seeking radiopharmaceutical 99mTc-MDP in defects of the mandibula was quantitated from scintigraphic images. Activity ratios were calculated by means of ROI-technique. The four selected regions contained two control regions and two with mandibula defects. One defect was filled with a fibrin bonding agent and one remained unfilled. The time course of the ratios showed a significant higher uptake of 99mTc-MDP in the region of the filled defect in comparison with the unfilled defect. The measurement of the residual defect areas from histological sections prepared 18 weeks after introduction of the defects confirmed the much more intensive ossification in the filled defects which could also be derived from the evaluation of the scintigrams. The results indicate that it is possible to follow up osseous repair by quantitative evaluation of scintigraphic images.